This contribution deals with social justice in healthcare financing in Germany. It starts from the observation that social justice – although often referred to in the public debate – is nei-ther explicitly conceptualized nor empirically measured. Our paper provides (1) a theoreti-cal framework and (2) a timely empirical basis, reflecting fairness in financing in the status quo of the German healthcare system. With regards to the first point, we recur to the norma-tive concept underpinning the WHO Report 2000. After summing up the critique the WHO study provoked, we extract that (1) healthcare premiums should not be risk-dependent, (2) all households with equal disposable income should make equal contributions (horizontal justice), and (3) higher income should lead to higher contributions (vertical justice). For the measurement of fair financing in the German healthcare system, we calculate the Kakwani-Index (overall index and partial indices) based on most recent available empirical data set of the Sample Survey of Income and Expenditure 2003 (EVS 2003). Our results for the overall Kakwani-Index show that healthcare financing in Germany has become slightly less regres-sive (from -0.045 to-0.041) within the past 15 years. Furthermore, we find some interesting changes in the partial indices. Finally, we point at the limits the Kakwani-Index imposes on the measurement of fair financing in the German healthcare system from a methodological perspective.